Reel mower with cutting units suspended by double A arm suspensions

ABSTRACT

A reel mower has a plurality of reel cutting units. Each reel cutting unit is connected to a frame of the reel mower by its own double A arm suspension that lowers a reel cutting unit into a cutting position in a tail down orientation and that levels the reel cutting unit out as it lifts the reel cutting unit into a transport position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of previously filed provisionalapplication Ser. No. 61/133,285, filed Jun. 27, 2008.

TECHNICAL FIELD

This invention relates to a reel mower having one or more reel cuttingunits that each comprises a rotatable cutting reel that sweeps grassagainst a sharpened bedknife for shearing the grass against thebedknife.

BACKGROUND OF THE INVENTION

Reel mowers having a self propelled mower frame and mounting a pluralityof reel cutting units are well known for precision mowing of grass. Insuch mowers, the reel cutting units typically are self-supporting androll over the ground during cutting using one or more ground engagingrollers carried on the reel cutting unit itself. A suspension mountseach such reel cutting unit to the mower frame so that the reel cuttingunits are propelled by motion of the mower frame. The suspension isdesigned to allow the reel cutting unit various degrees of freedom ofmotion relative to the suspension by means of which the reel cuttingunits can individually adapt themselves to the contours of the ground toprovide a higher quality of cut.

In recent times, there has been an increasing focus on further improvingthe quality of cut. The goal is to cut the grass at low heights of cutwith few or no discernible flaws of any type. Thus, to the extent priorart suspensions permitted reel cutting units to cut grass with anyunevenness in the cut that could be seen by the visible eye, or theextent prior art grass collectors attached to such reel cutting unitspermitted grass clippings to fall out or be left on the cut grass patheven in minute quantities, the customers of such equipment are becomingincreasingly less tolerant of such imperfections. It would be an advancein the art to provide suspensions that allow the reel cutting units toprovide a more uniform and even cut and to provide grass collection thatminimizes or eliminates any stray clippings from being left on the cutgrass path. This invention is directed in part to such improvements.

Another important aspect of such mowers is how easily they can beserviced. In this regard, certain of the reel cutting units, such as thecenter rear cutting unit in a triplex configuration, are generallylocated underneath the mower frame. Access to such a cutting unit isthus difficult. Moreover, the cutting units themselves can be difficultto remove from the rest of the mower, requiring that they be bolted orunbolted to the mower suspension. The same is true for the drive motorsthat might be attached to the reel cutting units to power the rotatablereels thereof. Thus, it would be a further advance in the art, and oneto which this invention is also directed, to provide cutting units thatcan be quickly and easily detached from their suspensions, that havedrive motors that can be quickly and easily detached from the cuttingunits, and to have a way to more easily access any obstructed cuttingunits, such as the center rear cutting unit mentioned above.

SUMMARY OF THE INVENTION

One aspect of this invention relates to a reel mower having a mowerframe supported for rolling over the ground. A power source is carriedon the mower frame. An operator's station is also carried on the mowerframe for supporting an operator thereon. A plurality of reel cuttingunits is further carried on the mower frame. A suspension operativelyconnects each reel cutting unit to the mower frame. Each suspension foreach reel cutting unit includes a pair of pivotal suspension armscomprising an upper suspension arm and an underlying lower suspensionarm.

Another aspect of this invention relates to a reel mower of the generaltype noted above. In this aspect, the suspension instead of that setforth above includes instead a substantially vertical pivot axis aboutwhich the reel cutting unit pivots to permit the reel cutting unit toyaw relative to the mower frame during turns of the mower frame when thereel cutting unit is in engagement with the ground in a cuttingposition. The vertical pivot axis is inclined or canted relative tovertical at a negative angle that points rearwardly relative to the reelcutting unit and relative to vertical as one proceeds downwardly alongthe angle of inclination.

Yet another aspect of this invention relates to a reel mower of thegeneral type noted above. In this aspect, the suspension instead of thatset forth above includes a plurality of transversely spaced, pivotalclamps that tightly clamp the reel cutting unit against a remainingportion of the suspension when the clamps are tightened to therebyreleasably attach the reel cutting unit to the remaining portion of thesuspension. A tab or finger is provided that can be moved back and forthmanually by an operator in opposite directions to loosen and tighteneach pivotal clamp without using a tool to thereby allow the reelcutting unit to be quickly detached from and attached to the remainingportion of the suspension, respectively.

An additional aspect of this invention relates to a reel mower of thegeneral type noted above. In this aspect, the suspension instead of thatset forth above includes a cutting unit carrier frame that pivotallyconnects to the cutting unit frame such that the reel cutting unitpitches fore and aft relative to the cutting unit carrier frame about asubstantially horizontal pitch axis. A grass basket is provided havingan open mouth through which the grass clippings are thrown into thegrass basket for collection therein. The grass basket is pivotal on thecutting unit carrier frame such that gravity acting on the grass basketcauses the grass basket to pivot towards the reel of the reel cuttingunit during operation of the reel cutting unit. At least a portion ofthe grass basket abuts against a portion of the cutting unit carrierframe to maintain a lower lip of the open mouth of the grass basket at apredetermined clearance to the cutting reel with such clearanceremaining substantially constant even as the reel cutting unit pitchesback and forth about the pitch axis

One more aspect of this invention relates to a reel mower of the generaltype noted above. In this aspect, the suspension instead of that setforth above simply operatively connects the reel cutting unit to themower frame. A grass basket is provided for collecting grass clippingscut by the reel cutting unit. The grass basket has a weight thatincreases with the amount of grass clippings held in the grass basket.The grass basket is operatively connected to a cutting unit frame of thereel cutting unit in a manner that transfers the weight of the grassbasket to the reel cutting unit such that the weight of the reel cuttingunit is borne by the cutting unit as the cutting unit rolls on theground. A counterbalance system offsets increasing weight of the grassbasket. The counterbalance system comprises at least one biasing memberfor applying a biasing force to the suspension in a direction that tendsto counterbalance the weight of the reel cutting unit including theweight of the grass basket, a sensor for detecting increasing weight ofthe grass basket due to the grass basket becoming more loaded with grassclippings, and an actuator responsive to the sensor for acting on thebiasing member to increase the biasing force to counteract increasingweight of the grass basket.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention will be described more completely in the followingDetailed Description, when taken in conjunction with the followingdrawings, in which like reference numerals refer to like elementsthroughout.

FIG. 1 is a perspective view of one embodiment of a reel mower accordingto this invention, namely a riding greensmower, particularlyillustrating a triplex riding greensmower with the two front reelcutting units and the center rear reel cutting unit being disposed in atipped up, elevated service position;

FIG. 2 is another perspective view of the mower of FIG. 1, particularlyillustrating a pivotal floorboard section having been pivoted to theside to allow access to the center rear cutting unit from between thefront cutting units and particularly illustrating the seat and controlconsole of the operator's station having been pivoted to the side andthe rear engine hood having been pivoted to the rear to allow access tothe engine compartment of the mower;

FIG. 3 is a perspective view of a portion of the mower of FIG. 1,particularly illustrating the right front tire of the mower and theright front reel cutting unit with the grass basket attached to the reelcutting unit and with the reel cutting unit being disposed in a lowered,operative cutting position;

FIG. 4 is a side elevational view of the portion of the mower shown inFIG. 3;

FIG. 5 is a side elevational view of a portion of what is shown in FIG.3, particularly illustrating the double A arms and steering headportions of the suspension that suspends the cutting unit from the frameof the mower as well as the illustrating the lift and lower actuator forlifting and lowering the cutting unit relative to the ground with thesteering head permitting yaw of the cutting unit about a yaw axisrelative to the double A arms;

FIG. 6 is a rear perspective view of what is shown in FIG. 5;

FIG. 7 is a rear perspective view similar to FIG. 6, but with the liftand lower actuator having been removed, the upper arm having beenremoved, and with the three pivot bushings of the upper arm having beenexploded off the ball joints on which such bushings are normallyreceived, all for the purpose of clarity;

FIG. 8 is a front perspective view of what is shown in FIG. 5, but withthe lift and lower actuator and the steering head having been removed,all for the purpose of clarity;

FIG. 9 is a front perspective view similar to FIG. 8, but with the lowerarm having been removed, with a pair of grass basket counterbalancetorsion springs having been exploded forwardly, and with thecounterbalance actuator having been added thereto;

FIG. 10 is a front perspective view of the reel cutting unit shown inFIG. 3 connected to the steering head of the suspension by the remainingcomponents of the suspension, namely by the transverse links forallowing roll of the cutting unit relative to the steering head about aroll axis and by the cutting unit carrier frame attached to thetransverse links including the pitch arms of the carrier frame forallowing pitch of the cutting unit relative to the carrier frame about apitch axis;

FIGS. 11A-11D are side elevational views of the reel cutting unit shownin FIG. 3, particularly illustrating the reel cutting unit being on theground in the cutting position thereof in FIG. 11A, being lifted off theground in FIG. 11B into an intermediate position between the cuttingposition and a raised transport position, being in the raised transportposition in FIG. 11C, and being lifted further out of the raisedtransport position to a raised service position in FIG. 11D;

FIG. 12 is a front perspective view similar to FIG. 10, particularlyillustrating the steering head, the cutting unit carrier frame, a grassbasket support member, and the reel cutting unit exploded relative toone another;

FIG. 13 is a front perspective view of what is shown in FIG. 10, butwith the reel cutting unit having been removed for the sake of clarity,and particularly illustrating the clamps for removably holding the reelcutting unit to the cross member of the carrier frame with one clampbeing shown open and one clamp being shown closed;

FIG. 14 is a front perspective view similar to FIG. 13, but particularlyillustrating the pitch arms and cross rod of the carrier frame havingbeen separated from the cross member of the carrier frame to illustratehow the reel cutting unit is removed as an entire unit from the mower ofFIG. 1;

FIG. 15 is an exploded perspective view of the open clamp shown in FIG.13;

FIG. 16 is a front perspective view of one end of the reel cutting unitof FIG. 3, particularly illustrating an electric drive motor that powersthe rotatable reel attached to the frame of the cutting unit by apivotal wire form;

FIG. 17 is a perspective view similar to FIG. 16, but with a hydraulicdrive motor in place of the electric motor of FIG. 16, and particularlyillustrating the wire form used to attach the drive motor and how thatwire form coacts with a cradle that forms a pair of seats for receivingportions of the wire form;

FIG. 18 is a perspective view similar to FIG. 17, but from a slightlydifferent angle, to better show one of the wire form receiving seats ofthe cradle;

FIG. 19 is a perspective view similar to FIG. 17, particularlyillustrating the drive motor and the seat forming cradle having beendisengaged from the wire form and having been slid to the side to removethe drive motor from the reel cutting unit;

FIG. 20 is a perspective view similar to FIG. 19, but showing the seatforming cradle having been slid to the side of the drive motor toillustrate that the cradle and drive motor are two separate pieces thatare merely clamped together by the wire form when the drive motor isheld or attached to the reel cutting unit by the wire form;

FIG. 21 is a front perspective view of the reel cutting unit of FIG. 3,particularly illustrating the reel cutting unit and the grass basketsupport member of the reel cutting unit but without the grass basket inplace;

FIG. 22 is a perspective view similar to FIG. 21, but illustrating thereel cutting unit having been installed on the grass basket supportmember;

FIG. 23 is a perspective view similar to FIG. 22, but showing the grassbasket having been separated into two exploded basket and top hand gripportions for the purpose of clarity with such portions normally beingfixed to one another;

FIG. 24 is a perspective view similar to FIG. 23, but taken from therear of the reel cutting unit rather than from the front of the reelcutting unit;

FIG. 25 is a perspective view similar to FIG. 24, but showing the rearportion of the grass basket in exploded form to better illustrate theattachment of the grass basket to the grass basket support member;

FIG. 26 is a rear perspective view of the reel cutting unit of FIG. 3,particularly illustrating the grass basket support member from the rearthereof but without the grass basket being attached to the grass basketsupport member;

FIG. 27 is a perspective view similar to FIG. 24, but showing the grassbasket in an assembled form installed on the grass basket support memberbut with a portion of the frame of the reel cutting unit having beenremoved to show how a side wall of the grass basket abuts against aforward facing edge of one of the pitch arms of the reel cutting unit;and

FIG. 28 is a side elevational view of the side wall/forward edgeabutment illustrated in FIG. 27, particularly illustrating thecircumference of the rotatable cutting reel of the reel cutting unit.

DETAILED DESCRIPTION The Overall Mower

FIGS. 1 and 2 illustrate one embodiment of a mower 2 according to thisinvention. Mower 2 comprises a frame 4 supported for rolling over theground by a pair of front wheels 6 f and a single rear wheel 6 rarranged in a triangular configuration. The rear of mower frame 4includes an engine compartment 10 that is normally covered and enclosedby an engine shroud or hood 8. An internal combustion engine or othersuitable power source, such as a battery pack, hybrid electric drivesystem, fuel cell, etc., is mounted in engine compartment 10. Variousother components can be housed on or adjacent the engine within enginecompartment 10, such as drive train components, controls, etc.

A hydraulic system (not shown) is carried on mower frame 4 and ispowered by the engine for providing pressurized hydraulic fluid flow forpowering various components of mower 2. For example, the hydraulicsystem includes an engine driven hydraulic pump that powers one or morehydraulic motors that drive one or more of wheels 6 to cause mower 2 tobe self propelled. Typically, front wheels 6 f are driven by thehydraulic system while rear wheel 6 r may or not be driven dependingupon whether mower 2 is in a two wheel drive (2WD) or three wheel drive(3WD) configuration. The single rear wheel 6 r could be replaced by apair of rear wheels 6 r and mower 2 could have a four wheel drive (4WD)configuration if both rear wheels 6 r are also driven. The numbers ofwheels 6 carried on mower frame 4, their placement relative to oneanother on mower frame 4, and whether all or only some of wheels 6 aredriven can obviously vary.

An operator's station is carried on mower frame 4. The operator'sstation includes a seat 12 for carrying a seated operator. A controlconsole 14 carrying various operational controls is mounted adjacent oneside of seat 12. Control console 14 and seat 12 are together carried onan operator's station subframe 16.

The front of mower frame 4 in advance of seat 12 has a U-shaped framemember 18 that opens towards the front to create an open space 20 infront of seat 12. During normal operation of mower 2, open space 20 isclosed to access from the front by an upwardly inclined footrest 22 thatextends in front of seat 12. If one were to try and walk into space 20from the front, one would hit footrest 22 and be prevented from reachingopen space 20. The operator can rest his or her feet on footrest 22while the operator is operating mower 2. If desired, various acceleratorand foot pedal controls (not shown) can be located on a portion offootrest 22 for use by the operator in controlling the traction speed ofmower 2.

A steering system comprises an L-shaped steering column 24 that mounts asteering wheel 26. Steering column 24 is cantilevered from one side ofmower frame 4 such that the long leg of the L-shape extends verticallyalong one side of mower frame 4 and the short leg of the L-shape ishorizontal and extends inwardly in front of operator's seat 12. Steeringwheel 26 is located on the short, horizontal leg of steering column 24immediately in advance of operator's seat 12 to allow an operator who isseated on seat 12 to steer mower 2. Rotation of steering wheel 26 by theoperator pivots the single rear wheel 6 r about a vertical axis forsteering mower 2. Alternatively, steering wheel 26 can be used to pivotor steer other of the wheels 6. However, in the three wheelconfiguration depicted in FIGS. 1 and 2, it is preferred that the singlerear wheel 6 r be the steerable wheel.

Various reel cutting units 28 are carried on mower frame 4 in a triplexgang configuration. Cutting units 28 comprise a pair of front cuttingunits 28 f carried in advance of front wheels 6 f with front cuttingunits 28 f being separated transversely from one another by a gap. Acenter rear cutting unit 28 r is carried behind front cutting units 28 fand is located to cover the gap between front cutting units 28 f so thatmower 2 cuts a single unbroken swath of grass in each pass of mower 2.Center rear cutting unit 28 r is located on mower frame 4 generallybetween front wheels 6 f of mower frame 4 and in advance of rear wheel 6r.

Other gang configurations of cutting units 28 could be used. Inaddition, additional rear cutting units 28 r could be added to mowerframe 4 on either side of center rear cutting unit 28 r to expand thetriplex configuration to a fiveplex configuration, and additional frontcutting units 28 f could be added outboard of each of front cuttingunits 28 f to expand a fiveplex to a sevenplex.

Access to the Engine Compartment and to the Center Rear Cutting Unit

Referring now to FIG. 2, engine hood 8 can be pivoted upwardly andrearwardly on mower frame 4 about a transverse pivot axis tosubstantially expose engine compartment 10 and more particularly toexpose the rear of engine compartment 10. With engine hood 8 pivoted toits open position as shown in FIG. 2, any components within enginecompartment 10 that would have been covered by hood 8 are exposed. Thesecomponents can be reached and easily serviced by someone who simplystands to one side of the rear of mower frame 4. Thus, simply pivotinghood 8 upwardly and rearwardly leads to easier service or maintenancefor much of engine compartment 10.

However, the front of engine compartment 10 is covered, not by enginehood 8, but by operator's seat 10 and control console 14. Thus, subframe16 is pivotally carried on mower frame 4 for rotation about alongitudinal pivot axis such that subframe 16, and thus operator's seat12 and control console 14, can be pivoted 90° to one side of mower frame4 as also shown in FIG. 2. The steering system is not, however, carriedon subframe 16 and so does not pivot with subframe 16. Thus, whenoperator's seat 12 and control console 14 are pivoted to the side asshown in FIG. 2, steering column 24 and steering wheel 26 remain intheir usual location on mower frame 4.

The purpose of pivoting subframe 16 to the side of mower frame 4 asshown in FIG. 2 is to expose or open up the front of engine compartment10 for service or maintenance. Obviously, engine hood 8 can be pivotedupwardly and rearwardly, or subframe 16 can be pivoted to the sideindependently and separately from one another, depending upon whetherone wishes to expose the rear of engine compartment 10 or the front ofengine compartment 10. For example, if the components that needservicing are located in the rear of engine compartment 10 and are onlycovered by hood 8, then only hood 8 need be pivoted and subframe 16 canstay in its normal, non-pivoted orientation. However, the entire enginecompartment from front to rear can be exposed if so desired by pivotingboth subframe 16 and engine hood 8.

Footrest 22 located in front of operators' seat 12 is preferablyprovided in two portions. The first portion comprises a fixed footrest22 f that is fixed to mower frame 4 on the right of mower frame 4. Thesecond portion is a pivotal footrest 22 p that pivots at the left sideof mower frame 4 about a longitudinal pivot axis. Fixed footrest 22 fmounts whatever foot pedal controls are used on mower 2. Fixed footrest22 f is very narrow compared to pivotal footrest 22 p. For example,fixed footrest 22 f extends laterally only 10 to 20% or so of the entirewidth of footrest 22 while pivotal footrest 22 p fills in the remaining80% to 90% or so the width of footrest 22.

As shown in FIG. 1, pivotal footrest 22 p has a usual, operationalposition in which it is rotated down and is flush with fixed footrest 22f as shown in FIG. 1. In this position, pivotal footrest 22 p blocksaccess to open space 20 formed by U-shaped frame member 18.Alternatively, as shown in FIG. 2, pivotal footrest 22 p can be rotated90° to the side to an access or service position in which pivotalfootrest 22 p extends vertically and does not block open space 20.

When pivotal footrest 22 p is rotated into its access or serviceposition as shown in FIG. 2, the path is clear for an operator or amechanic to walk back into open space 20 defined by frame member 18through the opening or gap that exists between front cutting units 28 fas indicated by the arrow A in FIG. 2. Center rear cutting unit 28 r islocated on mower frame 4 at least partially within open space 20 thoughthe back of center rear cutting unit 28 r might be tucked in back behindthe cross bar of frame member 18. Thus, merely by pivoting pivotalfootrest 22 p to the side as shown in FIG. 2, one can easily reachcenter rear cutting unit 28 r to service, adjust or even remove centerrear cutting unit 28 r. This task is further eased since each cuttingunit 28 disclosed herein, including center rear cutting unit 28 r, canbe raised up off the ground into a service position where the cuttingunit is tilted up by an angle of approximately 50° to 70° or so, asshown by the tipped up orientation of cutting units 28 in FIG. 1. Whencenter rear cutting unit 28 r is disposed in this tipped up serviceposition, even the undersides of the cutting unit are exposed to one whohas reached open space 20 by flipping up pivotal footrest 22 p and bywalking back through the gap between front cutting units 28 f.Alternatively, front cutting units 28 f can be removed from theirsuspensions 30 (as described hereafter in the section entitled EasilyRemovable Cutting Unit) to more completely open up the path to centerrear cutting unit 28 r.

In many prior art mowers, center rear cutting unit 28 r is locatedentirely or almost entirely under mower frame 4. While center rearcutting unit 28 r can typically be lifted and lowered off the ground, itis difficult to service, adjust or maintain such a cutting unit becauseof the interference with the overlying mower frame 4. However, becauseof the placement in mower 2 of center rear cutting unit 28 r at leastpartially within an open space 20 at the front of mower frame 4, andbecause the operator can selectively access space 20 simply by flippingup a pivotal footrest 22 p, the difficulty of servicing, adjusting ormaintaining center rear cutting unit 28 r has been substantiallydecreased. This is an advantage to anyone who might work on such mowers.

In other prior art mowers, attempts have been made to increase the easeof servicing a center rear cutting unit by carrying the cutting unit ona pivotal arm to allow the center rear cutting unit to be selectivelyswung out from under the mower frame to a service position in which thecenter rear cutting unit is beside the mower frame and thus is exposed.While effective, this solution involves the use of additional structure,such as the pivotal arm and various latches and the like for latchingthe arm and the center rear cutting unit in its usual operationalposition. It also complicates the task of lifting and lowering thecenter rear cutting unit off the ground.

These disadvantages are avoided in the approach disclosed herein. Allthat is required is to appropriately locate center rear cutting unit 28r at least partially within open space 20 at the front of mower 2 and toallow an operator to access this space. Access is easily andinexpensively provided simply by pivoting a portion of footrest 22, apart that would normally be present on mower 2. Thus, no additionalparts are required except for the pivot pin(s) that mount pivotalfootrest 22 p to mower frame 4.

In addition, the increased access provided by pivotal footrest 22 p toopen space 20 at the front of mower frame 4 is useful in allowing accessto the front of engine compartment 10 from the front of mower 2 ratherthan simply from the side. Thus, with pivotal footrest 22 p pivoted tothe side as shown in FIG. 2, and with subframe 16 also pivoted to theside as shown in FIG. 2, a person standing in open space 20 can easilyreach into and service the front of engine compartment 10 from thefront. This allows such a person to more easily service any componentsthat are located at the right front of engine compartment 10. Suchcomponents would otherwise be the furthest away from someone standingadjacent the left side of mower frame 4 which is where someone wouldotherwise have to stand to service the front of engine compartment 10when subframe 16 is pivoted to the right side of mower 2.

Various modifications of the fixed and pivotal footrests are possible.For example, it is preferred that fixed footrest 22 f carry the footpedal controls for mower 2 since any linkages extending to such footpedal controls will remain in place and be undisturbed by pivoting theseparate pivotal footrest 22 p. However, if so desired, footrest 22could be split into two pivotal portions 22 p of more equal size withone portion pivoting to the right side of mower frame 4 and the otherportion pivoting to the left side of mower frame 4, i.e. opening andclosing like barn doors. The portion pivoting to the right side of mower2 could further be integrated with subframe 16 to pivot to the rightwith the subframe 16.

The Cutting Unit Suspension

Each cutting unit 28 is coupled to mower frame 4 by a suspension 30 thatlifts and lowers cutting unit 28 out of and into contact with theground, respectively. Suspension 30 also provides cutting unit 28 withthree degrees of freedom along orthogonal x, y and z axes to allow eachcutting unit to individually follow the contours of the ground. Becausesuspension 30 is identical from one cutting unit to another, thedescription of suspension 30 in conjunction with one cutting unit 28will suffice to describe suspensions 30 for all cutting units 28. Asdepicted in FIGS. 3-8, suspension 30 is shown in the position in whichcutting unit 28 has been lowered into its operative cutting positionwith cutting unit 28 in rolling contact with the ground.

Suspension 30 includes an upper suspension arm 32 and an underlyinglower suspension arm 34. In the top plan view, each arm 32, 34 is shapedlike an A with a wider rear end and a narrower front end. Each arm 32,34 has a truss like beam structure and is preferably cast or formed asan integral one piece part. In other words, upper arm 32 is a first onepiece part and lower arm 34 is a second one piece part that is separatefrom upper arm 32.

Each arm 32, 34 has generally the same A shape in the top plan view andmay be referred to as an “A arm” because of this A top plan shape.However, arms 32, 34 have different side elevational shapes with lowerarm 34 having a fairly pronounced, downwardly facing, U-shaped gooseneck36 near the front end thereof. This allows the front of lower arm 34 tonest closer to the underside of the front of upper arm 32 than at therear. In other words, the fronts of arms 32, 34 are vertically closertogether than the rears of the arms 32, 34. See FIG. 5.

Each side of each arm 32, 34 at the rear thereof includes a circularbore 38 that extends generally in a vertical plane. The front of eacharm 32, 34 has a similar bore 38 that extends generally in a horizontalplane when cutting unit 28 is disposed in its operative cuttingposition. Pivot bushings 40 having a spherical seat (not shown) in theinterior thereof are disposed in each of these bores 38. Thus, bushing40 at the front of each arm 32, 34 will be generally horizontal whencutting unit 28 is in its operative cutting position and bushings 40 ateither side of the rear of each arm 32, 34 will be generally vertical.These orientations of bushings 40 have been found to be most effectivein absorbing the typical impact shocks experienced by cutting unit 28during cutting of the grass.

Bushings 40 at the rear of each arm 32, 34 are pivotally journalled on apair of transversely outwardly extending rear ball joints 42 r. Thebushings 40 and ball joints 42 on which they are received, whether usedat the front or rear of each arm 32, 34, have the structure disclosed inU.S. Pat. No. 7,144,182, which patent is hereby incorporated byreference. Rear ball joints 42 r for each arm 32, 34 are aligned withone another to form a common, transversely extending, substantiallyhorizontal pivot axis. In this respect, the spherical head of each balljoint 42 r is received within the interior spherical elastomeric orpolymeric seat of bushing 40. Thus, upper arm 32 pivots on mower frame 4about a first horizontal pivot axis denoted as x1. Similarly, lower arm34 pivots on mower frame 4 about a second horizontal pivot axis denotedas x2. See FIG. 5. Note that rear ball joints 42 r for only upper arm 32have been shown in FIGS. 3-7 with rear ball joints 42 r for lower arm 34having been omitted from the figures for the purpose of clarity.

Bushing 40 at the front of each arm 32, 34 is pivotally journalled on avertically extending front ball joint 42 f in the same manner as forbushings 40 and rear ball joints 42 r. Instead of being fixed to mowerframe 4, however, front ball joints 42 f for the arms are clamped inplace to a steering head 44. Referring to FIGS. 6 and 7, steering head44 includes a somewhat planar vertically extending body 46. Body 46 hasa pair of rearwardly extending, transversely spaced posts 48 thatterminate in longitudinal pods or hubs 50 at the rear thereof.

Front ball joints 42 f are secured to the backside of body 46 ofsteering head 44 with the ball portion of the ball joint 42 f for upperarm 32 extending downwardly from body 46 as shown in FIG. 7. The clampthat fixes this ball joint 42 f to the backside of body 46 has beenremoved in FIG. 7 for the purpose of clarity. Front ball joint 42 f forlower arm 34 is similarly mounted to the backside of body 46, but isinverted such the ball portion of that ball joint extends upwardly intobushing 40 at the front of lower arm 34. FIG. 8. depicts the invertedrelationship of the two front ball joints 42 f relative to one another.The upper and lower arms 32, 34 are connected together for jointrotation about their respective pivot axes x1 and x2 since the fronts ofthe arms are each connected to a single common piece, namely to steeringhead 44 as shown in FIG. 5.

As further shown in FIG. 5, when cutting unit 28 is in the operativecutting position, front ball joints 42 f and their stems are aligned ona yaw pivot axis to allow cutting unit 28, which is carried beneathsteering head 44, to steer or yaw about a yaw pivot axis denoted as z.This allows cutting unit 28 to better turn or track over the groundduring turns of mower 2 without skidding or dragging cutting unit 28over the turf. The yaw pivot axis z forms one degree of freedom ofmotion for cutting unit 28. The yaw pivot axis z has a particular angleor inclination relative to vertical that will be described in moredetail hereafter in the section hereof entitled Negative Caster Angle.

Referring now to FIGS. 10 and 13, suspension 30 further includes agenerally U-shaped cutting unit carrier frame 52. Carrier frame 52extends transversely across the width of cutting unit 28 and has a pairof downwardly extending vertical pitch arms 54 at either end thereof.Carrier frame 52 is, in reality, a number of different parts that areclamped together when cutting unit 28 is installed and is in itsoperative cutting position. In another aspect of this invention, theseparts can be unclamped to easily remove cutting unit 28 from mower 2 asdiscussed hereafter in a section entitled Easily Removable Cutting Unit.However, for the purposes of describing suspension 30 of cutting unit28, carrier frame 52 and pitch arms 54 are, in effect, rigidly fixedrelative to one another to move together as a single unit when cuttingunit 28 is installed on mower 2.

Referring now to FIG. 13, carrier frame 52 is pivotally attached tosteering head 44 by a pair of front rigid links 56 f and a pair of rearrigid links 56 r. The upper ends of front links 56 f are pivotallyattached to the front ends of hubs 50 on posts 48 of steering head 44and the upper ends of rear links 56 r are pivotally attached to the rearends of hubs 50 on posts 48 of steering head 44. Similarly, the lowerends of the front and rear links 56 f, 56 r are pivotally secured to thefront and back of carrier frame 52. The links 56 f, 56 r in each pairare inclined relative to one another as taught in U.S. Pat. No.7,191,584, owned by the assignee of this invention, which patent ishereby incorporated by reference. This allows cutting unit 28 to roll orpivot side to side about a horizontal longitudinal roll axis indicatedas y in FIG. 13. This provides the second degree of freedom for cuttingunit 28.

The third degree of freedom for cutting unit 28 is provided by theconnection of the lower ends of pitch arms 54 to cutting unit 28 itself.As also shown in FIG. 13, the lower end of each pitch arm 54 has a pivothub 58. Pivot hubs 58 are pivotally connected to cutting unit 28 aboutthe axis of the rotatable cutting reel 60 of cutting unit 28. Pivot hubs58 of pitch arms 54 together define a horizontal transverse pitch axisindicated as x in FIG. 13, which pitch axis is the same as the axis ofrotation of cutting reel 60. Thus, cutting unit 28, which is not itselfshown in FIG. 13, can pivot or pitch fore and aft about the pitch axisby rocking fore and aft between pitch arms 54.

A lift and lower actuator 62, such as a hydraulic cylinder, is pivotallyconnected between mower frame 4 and upper arm 32. Referring to FIG. 5,when the actuator arm 64 is retracted into the cylinder of actuator 62,upper arm 32 is pivoted about its pivot axis x1 (as is lower arm 34about its pivot axis x2 since lower arm 34 is connected to upper arm 32through steering head 44) in a clockwise direction shown by the arrow Bin FIG. 11A. This raises steering head 44 to lift cutting unit 28 offthe ground. Extension of actuator arm 64 from the cylinder has theopposite effect, namely a lowering of steering head 44 and cutting unit28 relative to the ground.

Referring now to FIGS. 11A-11C, suspension 30 lifts cutting unit 28 fromits cutting position on the ground as shown in FIG. 11A into a raisedtransport position as shown in FIG. 11C. Cutting unit 28 is placed intothe transport position when the operator wishes to drive mower 2 fromone location to another at a transport speed that is higher than thecutting speed at which mower 2 is driven when cutting grass.

Suspension 30 allows cutting unit 28 to approach and depart the groundin a preferred tail down position as shown in FIG. 11B. Thus, whencutting unit 28 lands on the ground, it lands first on the rear roller66 r of cutting unit 28 and then pivots downwardly about rear roller 66r until front roller 66 f touches the ground last. Similarly, whencutting unit 28 lifts off the ground, front roller 66 f departs first,cutting unit 28 then pivots upwardly about rear roller 66 r, and rearroller 66 r leaves the ground last.

The tail down approach and departure of cutting unit 28 happens becausethe center of mass of cutting unit 28 is behind the pitch axis x ofpitch arms 54. Thus, when cutting unit 28 first lifts off the ground,cutting unit 28 first pitches or rocks rearwardly relative to pitch arms54 until pitch arms 54 engage against a stop (not shown) on some portionof mower frame 4 of cutting unit 28. At that point, the pitching actionof cutting unit 28 stops with cutting unit 28 being maintained in thetail down position. In FIG. 11B, cutting unit 28 is shown having rockedback in the direction of the arrows C with the frame of cutting unit 28having stopped out against pitch arms 54. However, this tail downorientation of cutting unit 28 relative to the ground is not itself newin the reel mower art. Prior Toro reel mowers have done the same thing.

However, in addition to maintaining the tail down orientation of cuttingunit 28 relative to the ground in landing or departing the ground,suspension 30 also does something quite unique. In lifting furtherupwardly into the transport position, namely in going from theintermediate position shown in FIG. 11B to the transport position shownin FIG. 11C, cutting unit 28 actually begins to level out into a morehorizontal orientation. This is due to a retrograde or opposite rotationof steering head 44 on the fronts of upper and lower arms 32, 34. Asupper and lower arms 32, 34 rotate in the direction of the arrow B,steering head 44 is actually rotated oppositely in the direction of thearrow D in FIGS. 11B and 11C. After pitch arms 54 lock against the frameof cutting unit 28, this opposite rotation D then pivots cutting unit 28from its tail down position back to a more level position whilesimultaneously moving cutting unit 28 back closer to the front wheel.

While FIG. 11C shows cutting unit 28 not completely level, suspension 30could be designed to bring cutting unit 28 even more level if steeringhead 44 is rotated further forwardly in the direction of the arrow C. Inaddition, another approach would be to use some type of biasing forcefrom springs (not shown) that would help accomplish this. For example,springs (not shown) could be used between steering head 44 and lower arm34 to help center steering head 44 to face directly forwardly aftercutting unit 28 reaches the transport position if steering head 44 andcutting unit 28 are initially skewed or canted about the yaw axis z atthe beginning of the lifting operation. Such centering springs (notshown) would be arranged to push against steering head 44 on either sideof a longitudinal centerline through steering head 44. This pushingaction would also bias steering head 44 further forwardly in thedirection of the arrow D, with steering head 44 pivoting furtherforwardly due to the flex in bushings 40, to level out cutting unit 28even more than is shown in FIG. 11C.

Regardless of how level cutting unit 28 gets in the transport positionthereof as shown in FIG. 11C, there is no doubt that it becomes morelevel and that it moves rearwardly with the rear roller 66 r of cuttingunit 28 getting closer to the adjacent wheel 6 f. This allows thevertical height of rear roller 66 r above the ground, indicated as h inFIG. 11C, to increase by a couple of inches over what would haveoccurred had the tail down orientation been maintained in the transportposition, e.g. the height h above the ground increases from 2 inches orso to 4 inches or so. This extra clearance helps cutting unit 28 avoidhitting ground obstacles and the like as mower 2 drives over the groundwith cutting unit 28 in the transport position while allowing cuttingunit 28 to be conveniently lifted by pivoting about a horizontal,transverse pivot axis x1. Prior art mowers often pivoted or folded thecutting units about horizontal, longitudinal axes in order to providesufficient ground clearance in transport, but this creates its own setof problems including exposing the undersides of the cutting units whilein transport.

In addition, as the cutting unit 28 moves into its transport position,the cutting unit is moved or tucked in rearwardly towards the wheel 6with the fore-and-aft clearance between the two, indicated as c in FIG.11 C, decreasing. When this happens with each of the two front cuttingunits 28 f in relation to the front wheels 6 f, the stability of mower 2in transport is improved. It decreases the moment arm between the centerof mass of cutting unit 28 f and the rotational axis of the adjacentfront wheel 6 f, thereby decreasing the tipping force exerted on mower 2by front cutting units 28 f when all of the cutting units 28 are intheir transport position. This enhances stability of mower 2 when goingup or down hills and the like. It decreases or potentially eveneliminates the need for counterweights carried on mower frame 4.

In moving between the various positions shown in FIGS. 11A-11C, thepivot axes x1 and x2 of upper and lower arms 32, 34 remain fixed tomower frame 4 and remain fixed relative to each other. However, it isdesirable to provide cutting unit 28 with an even more elevated serviceposition in which cutting unit 28 is tilted up at a relatively steepangle to expose the underside of cutting unit 28 for service ormaintenance. Such a service position is illustrated in FIG. 11D. Asshown in FIG. 11D, the operator or a mechanic has greater access to andability to reach front and rear rollers 66, the rotatable cutting reel60, and the bedknife of cutting unit 28. For example, with cutting unit28 in the service position shown in FIG. 11D, it is fairly easy toremove the bedknife for sharpening or adjustment or to remove andreplace front and rear rollers 66.

In going between the transport and service positions shown in FIGS. 11Cand 11D, respectively, actuator arm 64 of lift and lower actuator 62 isretracted even further into the cylinder while lower arm 34 is releasedfrom its fixed attachment to mower frame 4. In other words, the two rearball joints 42 r (not shown) that pivot lower arm 34 on mower frame 4are normally fixed to mower frame 4 by a latch (not shown) that engagesa yoke (not shown) that carries rear ball joints 42 r for lower arm 34.This locked or latched condition for lower arm 34 is the condition thatoccurs when cutting unit 28 is in its operative cutting position or itstransport position or in any intermediate position between the cuttingand transport positions. The latch is disengaged from the yoke whenactuator arm 64 is retracted further into the cylinder to begin puttingcutting unit 28 into the service position.

The disengagement of the latch can occur in many ways. As shown in FIG.6, actuator arm 64 of the cylinder has a front clevis 68 that is pinnedby a pin (not shown) to a flange 70 on upper arm 32. This pin alsopasses through a pair of apertured tabs 72 on a rotatable latch release74 carried on mower frame 4 beneath upper arm 32. See FIG. 7. Whenactuator arm 64 is moved from its transport to its service position,actuator arm 64 acting through the pin and tabs 72 finally rotates latchrelease 74 far enough to release the latch that locks or fixes the yokeholding the two rear ball joints for lower arm 34 to mower frame 4. Whenthis occurs, the rear of lower arm 34 and the two rear ball jointstherefor can now move off the pivot axis x2 about which they normallyrotate and will move forwardly and pivot in an arc about the pivot axisx1 of upper arm 32. This forward movement of the rear of lower arm 34 isdepicted by the gap g that forms between the rear of lower arm 34 andthe pivot axis x2 as shown in FIG. 11D. Rear ball joints 42 r for upperarm 32 that define the pivot axis x1 are always fixed in place on mowerframe 4.

In any event, releasing lower arm 34 for movement relative to mowerframe 4 when actuator arm 64 is retracted over its final range of travelallows lower arm 34 to move forwardly and pivot upwardly as needed aboutthe pivot axis x1 to permit cutting unit 28 to rise and dramaticallytilt or incline into the service position thereof. When actuator arm 64is extended to move cutting unit 28 from its service position back downto its transport position, the latch can be spring biased toautomatically reset itself and relatch the yoke that holds rear balljoints 42 r for lower arm 34 to mower frame 4 with rear ball joints 42 ragain aligned on axis x2 when the transport position is reached. Thus,cutting unit 28 is lifted by a single lift and lower actuator from itsusual cutting position in contact with the ground, through a raisedtransport position, and on into a raised and inclined service position,and vise versa, simply by extending or retracting actuator arm 64 ofactuator 62 through different ranges of travel.

While a service position is desirable, it is not necessary and could bedeleted in the design of suspension 30. If the service position weredeleted, then the structure that permits the service position to bereached, such as the latch that is released to release the rear balljoints 42 r for lower arm 34, could be deleted and the rear ball joints42 r for lower arm 34 would be fixed to some portion of mower frame 4.Alternatively, one could avoid using the service position simply byrestricting the stroke of actuator arm 64 to the range of travel neededto go between the cutting and transport positions only. Thus, theservice position can be considered to be an optional feature.

Various pushbutton or other controls can be employed on control console14 to allow the operator to power actuator 62 through any desired rangeor ranges of travel. For example, one button could be provided for goingfrom cutting to transport and another button could be provided for goingfrom transport to service. In addition, unlatching the latch that fixesor holds the rear of lower arm 34 to mower frame 4, and relocking thelatch, is done automatically as actuator arm 64 extends and retracts.The operator is not required to manually remove or reinstall a manuallatch.

Suspension 30 for cutting unit 28 comprises a pair of durable A armsthat are pivotally coupled to mower frame 4 and to steering head 44 thatcarries cutting unit 28 by a plurality of durable bushings 40 and balljoints 42. Such bushings and ball joints permit any twisting that isneeded as suspension 30 is lifted and lowered between its variouspositions. In addition, the arms 32, 34 and the rest of suspension 30are configured to allow a tail down landing or take off orientation ofcutting unit 28 relative to the ground while also providing a more leveland more rearward orientation of cutting unit 28 relative to theadjacent wheel 6 of mower 2 in the transport position, all while liftingand lowering cutting unit 28 by pivoting cutting unit 28 about atransverse pivot axis on mower frame 4. Finally, cutting unit 28 can besimply and easily placed into a more inclined and more elevated serviceposition without requiring any action on the part of the operator otherthan to continue to retract actuator arm 64.

Negative Caster Angle

As explained earlier, the yaw axis z provided by front ball joints 42 fof upper and lower arms 32, 34 when cutting unit 28 is in its operative,lowered cutting position is not strictly vertical. Instead, the yaw axisis inclined or canted relative to the vertical at a caster angle denotedas a in FIG. 5. This caster angle is a negative angle within the rangeof about 5° to 10°, and preferably about 6° or so, meaning that theangle of inclination points rearwardly relative to cutting unit 28 andrelative to a vertical reference line as one proceeds downwardly alongthe angle of inclination. Known prior art reel cutting units have casterangles that are either precisely vertical (a zero caster angle) or areat a forward angle (a positive caster angle), namely an angle thatpoints forwardly as one proceeds downwardly.

The Applicants have found that using a negative caster angle preventsthe side of cutting unit 28 on the inside of a turn from dipping orwanting to dip down towards the ground (due to the overturning moment onthe cutting unit from the suspension) during a turn of mower 2 andduring a corresponding turn of cutting unit 28. For example, when mower2 is a riding greensmower as depicted herein, mower 2 is often used in aclean up pass around the margins of the green after the middle of thegreen has been mowed in a plurality of back and forth straight passes onthe green. In such a clean up pass, mower 2 is turned or guided all theway around the periphery of the green to mow the grass at the periphery.In prior art greensmowers with positive or zero caster angles on cuttingunits 28, the suspension tended to force the side of cutting unit 28 onthe inside of the turn down towards the ground, causing the cut grassswath to have a slight, uneven washboard effect or pattern. Given thelow heights of cut at which greensmowers cut grass, and given the desirefor perfection of the mowed surface on the green of a golf course, thiswashboard effect or pattern is not desirable.

Now, with the negative caster angle disclosed herein, the force of theground acting on the rollers of cutting unit 28 during a turn, causesthe side of cutting unit 28 on the inside of the turn to remain levelduring turns. In effect, the negative caster angle disclosed hereintends to cause the side of cutting unit 28 on the inside of the turn torise up an amount that counteracts the overturning moment from thesuspension This avoids the washboard effect or pattern noted earlier andis, therefore, desirable.

Easily Removable Cutting Unit

Referring now to FIGS. 12-15, cutting unit carrier frame 52, as notedearlier, comprises a plurality of parts that can be clamped andunclamped from one another to ease the task of installing or removingcutting unit 28 from mower 2. With respect to this aspect of theinvention, carrier frame 52 comprises a cross member 76, a cross rod 78,and the pitch arms 54 that are carried at either end of cross rod 78.Cross rod 78 and pitch arms 54 carried by cross rod 78 are obviously nowseparate parts from cross member 76 of carrier frame 52. In other words,pitch arms 54 are not integrally connected to cross member 76 as theyare in the assignee's prior U.S. Pat. No. 7,191,584. Rather, pitch arms54 are carried on a separate cross rod 78 and such pitch arms 54 will befixed or connected to cross member 76 only when cross rod 78 isconnected to cross member 76. This can be done in this invention in aquickly and easily attachable and detachable manner to allow cuttingunit 28 to be easily removed from mower 2.

As shown in FIGS. 12 and 15, the underside of cross member 76 has aplurality of downwardly facing, U-shaped notches 80 at either endthereof. The top of cross rod 78 fits up into notches 80. In addition,as shown in FIGS. 13 and 14, cross member 76 has a pair of clamps 82disposed at either end thereof.

As shown in FIG. 15, each clamp 82 includes a pivotal clamp body 84 thatis pivotally journalled on a first pivot pin 86 carried on cross member76. Clamp body 84 carries a pivotal J-shaped hook 88 on a second pivotpin 90. When clamp 82 is closed, hook 88 of clamp 82 is positionedunderneath cross rod 78 to receive cross rod 78 and to draw cross rod 78tightly up against notches 80 in cross member 76. When clamp 82 is open,hook 88 has been released from engagement with cross rod 78 and has beenrotated out of the way of cross rod 78 to release the clampingengagement of cross rod 78 to cross member 76.

Clamp body 84 includes a rearwardly extending tab or finger 92 to allowthe user to manually open clamp 82 by rotating clamp body 84 about firstpivot pin 86 by pushing up and forwardly on finger 92 in the directionof the arrow E in FIG. 15. Assuming clamp 82 was closed to begin withwhen this happens, the rotation of clamp body 84 causes hook 88 to lowerand drop out of its clamping engagement against the bottom of cross rod78. Once hook 88 has released cross rod 78 in this manner, the user canthen flip hook 88 forwardly out of the way of cross rod 78. If the userthen pushes down and rearwardly on the raised finger 92 in the directionof the arrow F in FIG. 15 to reversely rotate clamp body 84 relative tocross member 76, hook 88 will then be elevated but will not catch orclamp beneath cross rod 78. In fact, in the open position of clamp 82,the user can even manually flip hook 88 all the way up so that it isresting vertically upright or even lying atop finger 92. Referring toFIGS. 13 and 14, an open clamp 82 is illustrated on the left of crossmember 76 and a closed clamp 82 is illustrated on the right of crossmember 76.

To relock clamps 82 in their clamping orientation, the user first pushesup and forwardly on finger 92 in the direction of the arrow E and flipshook 88 down to allow the J-shaped end of hook 88 to get beneath crossrod 78. Then, with hook 88 positioned to catch against cross rod 78, theuser simply pushes down and rearwardly on finger 92 in the direction ofarrow F to close clamp body 84 and to draw hook 88 upwardly into a tightlocking or clamping relationship to cross rod 78. Thus, clamps 82disclosed herein are one form of a simple, manually operable clampadapted for temporarily clamping cross rod 78 of carrier frame 52 tocross member 76 of carrier frame 52. Other types of clamps or temporarysecuring devices could be used.

When clamps 82 are both released, cutting unit 28, including thatportion of suspension 30 comprising cross rod 78 and pitch arms 54attached to cutting unit 28, can separate from the rest of suspension30. This separation is depicted in FIG. 14. It is preferred that therebe an upward biasing force of a small amount, e.g. 5 pounds, on upperand lower arms 32, 34 of suspension 30. Thus, as soon as clamps 82 arereleased, the rest of suspension 30 will lift slightly above cuttingunit 28 far enough to clear cross rod 78 and pitch arms 54. The operatoror mechanic can then very easily roll cutting unit 28 out from underupper and lower arms 32, 34 to remove cutting unit 28.

Installing cutting unit 28 is a simple reversal of the above steps. Theoperator or mechanic rolls cutting unit 28 back into place beneath upperand lower arms 32, 34 and positions cross rod 78 beneath cross member76. Then, the operator or mechanic takes both hands and pushes down onopposite ends of cross member 76 until notches 80 on cross member 76engage against the top of cross rod 78. While holding this downforce,the operator or mechanic can then close clamps 82 by pushing down onfingers 92 in the direction of the arrow F using his or her thumbs untilclamps 82 have tightly clamped cross rod 78 to cross member 76. Theinstallation is then complete.

The manner in which cutting unit 28 can be easily removed and installedis unparalleled in the mower art. When any grass baskets 140 are removedfrom cutting units 28, the two front cutting units 28 f are completelyaccessible from the front. So, too, is center rear cutting unit 28 rafter pivotal footrest 22 p is flipped to the side, as describedearlier. To remove any cutting unit 28, the operator or mechanic simplyhas to release two clamps 82 with a couple flicks of the wrist andwithout requiring any tools. No attachment bolts or screws have to belaboriously unbolted or unscrewed. Once clamps 82 are unclamped, theupward bias on the rest of suspension 30 causes suspension 30 to simplylift on its own up above cutting unit 28 which remains on the ground.The operator or mechanic can them simply roll cutting unit 28 forwardlyto get it out from under suspension 30 and to remove it from mower 2.Cross rod 78 that remains on cutting unit 28 forms a convenient handlefor rolling cutting unit 28 out. Removal of a cutting unit, which was alaborious and difficult process in many cases in the prior art, nowtakes only a few seconds.

Easily Removable Cutting Unit Motor

Cutting unit 28 carries a motor 94 of some type, typically a hydraulicmotor though electric or other motors could be used. Such motors areoften coupled to one of the side plates 96 of the frame of cutting unit28. Some type of drive connection extends between the drive shaft of themotor and the shaft of rotatable cutting reel 60 carried on cutting unit28. As the drive shaft of the motor is rotated, the shaft of cuttingreel 60 rotates. Thus, the helical blades of cutting reel 60 sweep thestanding grass against a sharpened cutting edge of the bedknife to shearthe standing grass off at whatever height of cut is determined by thevertical position of front and rear rollers 66 relative to the frame ofcutting unit 28. Rollers 66 that are in relatively raised positionsrelative to the cutting unit frame mean lower heights of cut and rollers66 that are relatively in lowered positions on the cutting unit framemean higher heights of cut.

As a part of the service friendly nature of mower 2 of this invention,motor 94 used on cutting unit 28, whether such motor 94 be a hydraulicmotor as shown, an electric motor, or some other type of motor, iseasily and quickly removable from the frame of cutting unit 28. Thisaspect of the invention is shown in FIGS. 16-20. An electric motor 94 eis depicted in FIG. 16 while a hydraulic motor 94 h is depicted in FIGS.17-20.

Referring first to FIG. 20, motor 94 has an enlarged attachment flange100 at one end. Flange 100 has a pair of bores 102 on either side ofmotor 94. One bore 102 on flange 100 is illustrated in FIG. 20, the bore102 on the other side of motor 94 being obscured. The drive shaft 104 ofmotor 94 can be seen in FIG. 20 since motor 94 is not yet assembled tothe frame of cutting unit 28. In the past, motors of this type have mostoften been simply directly mounted or bolted to side plate 96 of theframe of cutting unit 28 using attachment bolts that pass inwardlythrough the bores 102 on flange 100 of motor 94 and into correspondingopenings 106 in side plate 96.

Motor 94 as depicted in FIGS. 17-20 does not show the hydraulic hoseconnections thereto. These extraneous portions of motor 94, which arenot essential to understanding the quickly removable nature of motor 94,have simply been removed from FIGS. 17-20.

Instead of using attachment bolts or screws, motor 94 is attached toside plate 96 using a pivotal wire form 112 and a cradle 114 having apair of seats 116 for coacting with portions of wire form 112 to holdmotor 94 against side plate 96 of cutting unit 28. As shown in FIG. 20,cradle 114 is shaped like a horseshoe with two upwardly extending legs118. Cradle 114 is not integrally formed as part of motor 94, though itcould be. Preferably, cradle 114 is a separate piece from motor 94 andthus can be used with existing motors from many manufacturers withoutthe need for retooling or redesigning standard, readily availablemotors. Thus, there is a cost advantage to making cradle 114 a separatepiece from motor 94 since it allows common, off the shelf motors 94 tobe used to power cutting unit 28. However, cradle 114 is preferablyremovably fixed to motor 94 or to attachment flange 100 by retainingring(s) (not shown) so that cradle 114 does not fall off motor 94 duringinstallation and removal of motor 94.

As shown in FIG. 20, legs 118 of cradle 114 on the backside each have analignment pin 120 that fits through one of the bores 102 on flange 100and then into an opening 106 therefor on side plate 96 of the frame ofcutting unit 28. In a sense, the alignment pins 120 are like theattachment bolts in the prior art except that they only align cradle 114to flange 100 and to side plate 96 of the frame of cutting unit 28instead of securing the parts together. The front side of each leg 118of cradle 114 is shaped to have an upwardly facing, inclined lip 122forming an open edge of a generally semi-circular seat 116. Seat 116 isbelow a curved cam 124 located at the top of each leg 118 of cradle 114.Curved cam 124 and seat 116 with the upwardly inclined lip 122 can bestbe seen in FIGS. 18-20.

Wire form 112 has a U-shaped central grip 126 having a pair of generallyvertical legs 128 that terminate in lower ends. Legs 128 of grip 126 arenot straight as they extend vertically, but have a couple of inclinedsections therein. Similarly, the top 130 of grip 126 is not horizontal,but is formed with a slight V-shape. In any event, grip 126 furtherincludes a horizontal locking pin 132 at the lower end of each of thevertical legs 128 of grip 126. Locking pins 132 extend transverselyoutwardly. Locking pins 132 are the portions of wire form 112 that willbe received in seats 116 formed in cradle 114 when motor 94 is held onor assembled to side plate 96 of the frame of cutting unit 28.

Wire form 112 is pivotally attached to side plate 96 of the frame ofcutting unit 28 by a U-shaped section 134 of wire form 112 connectingeach side of grip 126 to side plate 96. The U-shaped sections 134 ofwire form 112 extend in planes that are generally perpendicular to theplane of grip 126 of wire form 112. The legs 136 of each U-shapedsection 134 can be compressed towards one another or pulled away fromone another to some degree and the U-shaped section 134 can have a smallamount of rotation relative to side plate 96 at the end 138 where it isclamped to side plate 96. This movement in the U-shaped sections 134 ofwire form 112 is sufficient to allow the locking pins 132 of wire form112 to be placed into or pulled out of seats 116 in cradle 114.

As shown in FIG. 16, motor 94 has been assembled onto side plate 96 withcradle 114 having been slid in and abutted against flange 100 on motor94. Locking pin 132 on each of the vertical legs 128 of grip 126 isreceived in the upwardly facing, semi-circular seat 116 atop theupwardly inclined lip 122 thereof with grip 126 extending up above andaround motor 94 of motor 94. In this position, each locking pin 132 isbelow curved cam 124 on cradle 114. The force of wire form 112 and theengagement of the locking pin 132 on either side of motor 94 within seat116 on either side of cradle 114 are sufficient to tightly hold motor 94to side plate 96 of the frame of cutting unit 28.

If the user wishes to remove motor 94 from cutting unit 28, the onlything the user need do is to reach down, place his or her hand on top130 of grip 126 and pull firmly upwardly on grip 126. As the user doesso, the U-shaped sections 134 of wire form 112 can pivot or flex enoughto allow the locking pins 132 to be forced up past the curved cams 124on cradle 114 until the locking pins have risen past curved cams 124. Atthis point, there is nothing holding cradle 114 to side plate 96. Thus,motor 94 can simply be slid off to the side of side plate 96 asindicated by the arrow G in FIG. 19.

The hydraulic hose or other drive connections to motor 94 will also haveto be removed, either prior to or after the disconnection of motor 94from side plate 96, if motor 94 is to be completely removed and swappedout with another motor. However, if motor 94 can remain attached to thehydraulic hoses or drive connections at least temporarily, thedisconnection of such hoses or connections may not be necessary. Motor94 can simply be slid off and laid to the side of cutting unit 28 withthe hoses or drive connections still attached. But, in either case,motor 94 can be simply and quickly disconnected from cutting unit 28 bypulling up on grip 126 of wire form 112 to disengage wire form 112 fromseats 116 formed in cradle 114.

It is similarly easy to reattach motor 94. To do this, cradle 114 ascarried on flange 100 has its alignment pins 120 passing through bores102 in cradle 114.The assembled cradle 114 and motor 94 are abuttedagainst side plate 96 with the alignment pins 120 passing into theopenings 106 therefor on side plate 96. Then, the user need only grabtop 130 of grip 126 and push down on grip 126. This will flex and pivotthe U-shaped bottom sections 134 of wire form 112 sufficiently to allowthe locking pins 132 to be cammed over the cam surfaces 124 with lockingpins 132 finally snapping into seats 116 provided on cradle 114. Whenthis occurs, the force of wire form 112 will hold motor 94 firmly inplace on cutting unit 28.

As can be appreciated, removing and attaching motor 94 to cutting unit28 now takes only seconds. In conjunction with the quick and easyattachment and removal of cutting unit 28 from mower 2, the operator ormechanic's task in providing service is made vastly easier. Cutting unit28 can be pulled out and removed very quickly and without tools byopening two clamps 82. Once this is done, motor 94 driving cutting reel60 can be removed from cutting unit 28 simply by pulling up on grip 126of wire form 112, again without using any tools, and by then slidingmotor 94 off to the side. The laborious bolting and unbolting known inthe prior art is no longer required for either task.

Obviously, when both of these quick removal features are used togetheron the same mower 2, the ease of service is enhanced to its fullestextent. However, either feature could be used independently of theother. For example, one could use the easy removal feature of cuttingunit 28 using the two clamps 82 on a cutting unit 28 not having thequick removal of motor 94 provided by wire form 112, and vise versa.

The Grass Basket With Balanced Cutting Unit Weight Distribution

Each cutting unit 28 can be equipped with a grass basket 140 that may beoptionally attached to cutting unit 28 for collecting grass clippingsgenerated by the operation of cutting unit 28. As is typical in manyprior art reel cutting units, grass basket 140 is mounted forwardly ofrotatable cutting reel 60 of cutting unit 28. Grass clippings are thrownor deflected forwardly from cutting reel 60 to be collected in grassbasket 140. Periodically, grass basket 140 may be removed from cuttingunit 28 for dumping of the grass clippings at some disposal or dumplocation. Cutting unit 28 can be operated without grass basket 140attached thereto if the operator does not wish to collect the grassclippings.

Grass basket 140 is supported on a grass basket support member 142 thatis itself pivotally supported on cutting unit carrier frame 52. Grassbasket support member 142 is U-shaped having a transverse cross beam 144and pair of upwardly and forwardly extending support arms 146. Crossbeam 144 includes an outwardly extending trunnion 148 at either end.Each trunnion 148 is rotatably received in a pivot hub 150 carried ateither end of cross member 76 of carrier frame 52. See FIG. 12 for anillustration of trunnions 148 and pivot hubs 150 in an exploded,non-assembled relationship relative to each other.

Pivot hubs 150 are carried on arms 152 that extend rearwardly from crossmember 76 of carrier frame 52 as best shown in FIG. 26. Pivot hubs 150define the pivot axis of grass basket support member 142, which isindicated as x4 in FIGS. 4, 23, 24 and 26. Pivot axis x4 is locatedrearwardly of cross member 76 of carrier frame 52.

Support arms 146 of grass basket support member 142 have a pair ofoutwardly extending support pins 154 that are each aligned on a commonaxis indicated as x5 in FIGS. 23, 24 and 26. Referring to FIGS. 24 and25, the rear of grass basket 140 has a pair of slotted fingers 156 thatfit around support pins 154 to attach grass basket 140 to grass basketsupport member 142. The top of the basket includes a top hand grip 157.Top hand grip 157, in conjunction with a bottom hand hold 158 moldedinto the bottom of grass basket 140 near the front thereof as shown inFIG. 22, allows the operator to lift grass basket 140 off mower 2 or toplace grass basket 140 onto mower 2.

Two pivotal latches 160 are used to lock or secure grass basket 140 ontosupport pins 154 of grass basket support member 142. Pivotal latches160, only one of which is shown in FIGS. 24 and 25, are operated by apivotal latch release 162 that is carried under top hand grip 157. Latchrelease 162 can be squeezed in the direction of the arrow H in FIG. 25by the operator's hand when the operator is gripping top hand grip 157.When latch release 162 is so gripped and squeezed, pivotal latches 160rotate up and out of contact with support pins 154 as shown by the onelatch 160 that can be seen in FIG. 25. This releases grass basket 140for removal from or installation on support pins 154. When latch release162 is not being gripped and squeezed by the operator, spring biasing onlatch release 162 causes latches 160 to rotate downwardly until theyengage against and lock on support pins 154 to secure grass basket 140to support pins 154. This is what retains grass basket 140 on grassbasket support member 142.

FIGS. 23-25 show top hand grip 157, slotted fingers 156, latches 160 andlatch release 162 separated away from the basket portion of grass basket160, but only for the sake of clarity. Normally, the hand grip 157,slotted fingers 156, etc. are carried on and united with the basketportion as shown in FIGS. 3, 4, 27 and 28.

In any event, when grass basket 140 is attached to and carried by grassbasket support member 142, it is in a position to catch grass clippingsbeing generated by cutting unit 28 and thrown forwardly into grassbasket 140 through an open rearwardly facing mouth 141 of grass basket140. See FIG. 24. As the clippings accumulate in grass basket 140, theweight of grass basket 140 naturally increases. However, that weight istransferred to cutting unit 28 at the connection of the pitch arms 54 tothe cutting unit 28.

As noted earlier, the pitch arms 54 connect to the cutting unit 28around the axis of rotation of the cutting reel 60. The axis of rotationof the cutting reel 69 is midway or substantially midway between therotational axes of front and rear rollers 66 of cutting unit 28.Accordingly, the weight of grass basket 140 is equally distributedbetween front and rear rollers 66. In other words, as the weight ofgrass basket 140 increases, the amount of weight seen by front roller 66f increases by an amount equal to the increase seen by rear roller 66 r.Front roller 66 f does not become more heavily loaded than rear roller66 r.

This equal weight distribution between front and rear rollers 66 ispreferred since it helps minimize any change in the quality of the cutthat might occur from the increasing weight of grass clippings in grassbasket 140. The mower designer usually takes into account the weightdistribution of cutting unit 28 when grass basket 140 is not attached,or at least when grass basket 140 is empty, when attempting to achievethe best quality of cut that is possible. With grass basket 140 inplace, the quality of cut will be adversely affected by the weight ofgrass basket 140 and particularly by the dramatically increasing weightof grass basket 140 as it fills with clippings. This adverse affect isundesirably magnified if front roller 66 f is more heavily loaded withthe basket weight than rear roller 66 r. By keeping the weightdistribution substantially equal between front and rear rollers 66, theadverse changes in the quality of cut that occur with an increasingbasket weight are kept to a minimum.

The Counterbalanced Grass Basket

While adverse changes in the quality of cut from increasing grass basketweight can be minimized as noted above, such changes are not eliminated.Cutting unit 28 will have one quality of cut when grass basket 140 isempty or not installed on cutting unit 28 and a second quality of cutwhen grass basket 140 is fully loaded with perhaps 30 or more pounds ofgrass clippings. Keeping this weight equally distributed between frontand rear rollers 66 is a desirable thing to do.

To eliminate any adverse changes in the quality of cut from increasinggrass basket weight for a grass basket 140 that is carried on cuttingunit 28, a further improvement has been added to mower 2 to deal withthis increasing weight. This improvement comprises an activecounterbalance system that increases the upward biasing force on upperand lower arms 32, 34 of cutting unit suspension 30 for each 5 poundincrement of change in the weight of grass basket 140. This improvementis an optional addition to the balanced weight distribution featurenoted earlier. For example, a more basic or standard mower would beequipped with the balanced weight distribution and a more deluxe orpremium mower would be equipped with both the balanced weightdistribution and the active counterbalance system that will now bedescribed.

The active counterbalance system will be described first with referenceto FIGS. 8 and 9. A plurality of counterbalance torsion springs 164 arelocated on a portion of mower frame 4 on the pivot axis x2 of lower arm34. Springs 164 are located between rear ball joints 42 r of lower arm34. However, springs 164 remain on the pivot axis x2 and do not movewith rear ball joints 42 r of lower arm 34 when lower arm 34 moves offpivot axis x2 when cutting unit 28 is being lifted into the serviceposition thereof. Springs 164 always remain in place on pivot axis x2.

Referring to FIG. 9, springs 164 are located around a pivotal adjustmentshaft 166 that is rotatably journalled in that portion of mower frame 4that mounts springs 164. One end 168 of each spring 164 is hooked into aslot 170 in shaft 166. The other end 172 of spring 164 is free and isadapted to simply abut against some portion of lower arm 34 ofsuspension 30. Thus, suspension 30 will be biased upwardly by theabutting engagement of the free ends 172 of spring 164 against lower arm34 with the amount of the biasing force depending upon how tightly woundsprings 164 are around shaft 166. The more tightly wound, the higher thebiasing force.

A counterbalance actuator 174 extends between mower frame 4 and apivotal link 176 that is attached to one end of shaft 166. Actuator 174can comprise either a hydraulic or an electric actuator or the like.Actuator rod 178 is pivotally connected to the lower end of link 176. Asactuator rod 178 is extended, link 176 and shaft 166 are rotated in thedirection of the arrow J in FIG. 9 to more tightly wind springs 164around the axis of shaft 166.

Actuator rod 178 is automatically extended in concert with the increasein weight of grass basket 140. The extension occurs without requiringthe operator to manually control or activate actuator 174. A load sensor(not shown) of some type is positioned between grass basket supportmember 142 and cross member 76 of carrier frame 52. For example, grassbasket support member 142 has a central, upwardly extending, forwardlyfacing channel 180 forming a generally cylindrical housing 182 at theupper end thereof. See FIGS. 21 and 26. This housing 182 on grass basketsupport member 142 is directly behind and faces a similar housing 184located at the center of cross member 76 of carrier frame 52. The loadsensor can be arranged within and between these two housings 182 and 184to, in effect, be sandwiched between the two.

As grass basket 140 fills with grass clippings and its weight increases,grass basket 140 and grass basket support member 142 will pivotforwardly about the pivot axis x4 in the direction of the arrow K inFIG. 26. This will compress the load sensor between housing 182 onchannel shaped member 180 on grass basket support member 142 and housing184 on carrier frame 52. The compression of the load sensor is anindication of the amount of the weight increase of grass basket 140. Theload sensor sends a signal to some type of controller (not shown) onmower 2 so that the weight of grass basket 140 is monitored by thecontroller.

As noted previously, springs 164 are initially set to provide a smallamount of upward biasing force on upper and lower arms 32, 34 even whengrass basket 140 is empty. Thus, when grass basket 140 is removed andcutting unit 28 is disconnected from mower 2, upper and lower arms 32,34 rise up above cutting unit 28 to allow the operator or mechanic tosimply roll cutting unit 28 out. This aspect was previously discussed inthe section hereof entitled Easily Removable Cutting Unit.

Now, as grass basket 140 increases in weight when grass clippings arebeing deposited therein, for every 5 lb increase in the weight of grassbasket 140, as detected by the load sensor and monitored by thecontroller, the controller will send an adjustment signal to actuator174 to wind up springs 164 an amount sufficient to provide an additional5 lbs of upward spring biasing force on upper and lower arms 32, 34 ofactuator 174. This will balance out the increase in the weight of grassbasket 140 and return the weight of cutting unit 28 on the ground to itsdesigned nominal amount, whatever that might be. In other words, theweight of cutting unit 28 as it rolls over the ground is keptsubstantially constant with the increase in weight of grass basket 140not being transmitted onto cutting unit 28. Instead, this increase inweight is being constantly monitored and counterbalanced in 5 lb.Increments by the active counterbalance system just described.

It would be possible to detect smaller or larger increments of weightincrease as the trigger for making an adjustment in the force providedby springs 164. The adjustment could even be done on a substantiallycontinuous basis, though this is not preferred because the system wouldbe almost constantly making an adjustment in spring force. An incrementof 5 lbs. has been found by the Applicants herein to not be so large asto dramatically adjust the quality of cut provided by cutting unit 28.Thus, even allowing the weight of grass basket 140 to increase 5 lbs.before making an adjustment in springs 164 will not appreciablyadversely affect the quality of cut.

In addition, the counterbalance system can be used to compensate forchanges in the cutting unit weight depending upon whether an electricmotor 94 e or a hydraulic motor 94 h is used to power cutting reel 60.Electric motors 94 e are typically heavier than hydraulic motors 94 h.Thus, if a heavier electric motor 94 e is installed, the counterbalancesystem can be initially set to provide more upward biasing force on thesuspension than in the case of when lighter hydraulic motor is installedin an amount sufficient to counteract the increase in weight of theheavier electric motor 94 e compared to the hydraulic motor. In otherwords, the suspension should ultimately provide the same nominal netupward biasing force on cutting unit 28 regardless of variations inweight of the cutting unit 28 that result from changes in the weight ofthe motor 94 that is installed on cutting unit 28.

It would be possible on mower 2 to delete the active counterbalancedgrass basket feature. If this were to occur, then it would not benecessary to make grass basket support member 142 a separate member fromcross member 76 of carrier frame 52, trunnions 148 and 150 would nolonger be needed such that the pivot axis x4 of grass basket supportmember 142 would disappear, and the housings 182, 184, the load sensor,and the counterbalance actuator 174 would be deleted. In this event,some type of support arms 146 and/or support pins 154 would still beused to support grass basket 140 on carrier frame 52, but such supportarms 146 and support pins 154 would be fixed to some remaining portionof carrier frame 52, such as cross member 76. Even if the activecounterbalanced grass basket feature were deleted, some counterbalancesprings would most likely still be used to provide an upwardcounterbalance force on suspension 30, if for no other purpose than inconnection with the Easily Removable Cutting Unit described earlier,i.e. to allow suspension 30 to lift slightly when a cutting unit 28 isunhooked from suspension 30.

The Dual Pivot Axes of the Grass Basket

Grass basket 140 is actually provided with two pivot axes. The firstpivot axis is the axis x4 of grass basket support member 142 relative tocarrier frame 52 that carries cutting unit 28. This is the pivot axisabout which grass basket 140 rotates or pivots as it fills with grass.This is the pivot axis about which the pivoting motion of grass basketsupport member 142 is detected and sensed by the load sensor as theweight indication used in the active counterbalance system described inthe preceding section hereof.

However, grass basket 140 is also free to pivot, at least in a clockwisedirection as indicated by the arrow L in FIGS. 23 and 24, about supportpins 154 which attach grass basket 140 to grass basket support member142. The axis x5 of support pins 154 is actually a second pivot axis forgrass basket 140. Grass basket 140 can only pivot in the clockwisedirection L about the axis x5 as pivoting in the other direction issubstantially prevented during normal operation of mower 2. This is dueto the fact that grass basket 140 normally rides against pitch arms 54of suspension 30 to provide controlled clearance of a lower lip 186 ofmouth 141 of grass basket 140 relative to cutting reel 60. This aspectof mower 2 will be discussed hereafter in the section hereof entitledControlled Grass Basket Clearance to the Cutting Reel.

As grass basket 140 fills with grass and its weight increases, grassbasket support member 142 can pivot about the axis x4 to accommodatethis increase in weight and allow grass basket 140 counterbalance systemnoted earlier to function. This rotation about the axis x4 in thedirection of the arrow K is accompanied by a very slight rotation ofgrass basket 140 about the axis x5 in the direction of the arrow L. Inother words, as the weight of grass basket 140 increases and grassbasket support member 142 pivots, grass basket 140 and grass basketsupport member 142 will jackknife slightly about the axis x5 to permitthis pivoting motion of grass basket support member 142 in the directionof the arrow K.

Pivot axis x5 of grass basket 140 is further forward and substantiallyabove the pivot axis x4 of grass basket support member 142. This isimportant given the fact that the front of grass basket 140 issignificantly forward of cutting unit 28 when grass basket 140 isattached to cutting unit 28. Thus, when mower 2 encounters a sharpchange in elevation, such as when mower 2 descends a hill and then comesto a flat surface at the bottom of the hill, or vise versa, grass basket140 will experience the change in elevation before the rest of mower 2.In other words, the front of grass basket 140 will hit the flat surfacewhile the rest of mower 2 is still on the hill.

If only the pivot axis x4 were present and because basket 140 does notpitch with cutting unit 28, the forward propulsive force of mower 2 ongrass basket 140 would tend to drive grass basket 140 into the ground atthe change in elevation or into the flat surface in the example above.This would roll grass basket 140 forwardly against the ground, therebydamaging grass basket 140 by jamming it into the ground or potentiallydamaging the rest of mower 2. This is obviously undesirable.

However, when the above noted change in elevation scenario occurs, thepresence of the other pivot axis x5 that is forward and higher than thepivot axis x4 permits grass basket 140 to pivot in the direction of thearrow L to accommodate the transitory transition at the change inelevation. Thus, when grass basket 140 is driven against the flatsurface in the example noted above, grass basket 140 can sharply pivotor jackknife in the direction of the arrow L. When the rest of mower 2and cutting unit 28 reach the flat surface, then this temporary sharprotation will reverse until grass basket 140 reestablishes contact withpitch arms 54 of cutting unit 28. The presence of the second pivot axisx5 thus permits mower 2 to drive over sharp elevational changes betweena hill and a flat surface, or at elevational changes in a swale, withgrass basket 140 pivoting about the pivot axis x5 as need be toaccommodate this.

Controlled Grass Basket Clearance to the Cutting Reel

Grass basket 140 is attached to cutting unit 28 by grass basket supportmember 142 that is carried on carrier frame 52 for cutting unit 28.Carrier frame 52 is located downstream of two of the three axes offreedom about which cutting unit 28 can move in adapting to changes inground contour. In other words, carrier frame 52 is located below ordownstream of steering head 44, which provides freedom in the z or yawaxis, and is below the pairs or rigid inclined links 56, which providefreedom in the y or roll axis. Thus, grass basket 140 inherently yaws orrolls with cutting unit 28 and maintains a constant clearance relativeto cutting unit 28 about the y and z axes.

However, cutting unit 28 is free to pitch about the x axis and theproblem remains of how to keep lower lip 186 of mouth 141 of grassbasket 140 at a fairly constant and small clearance relative to cuttingreel 60. If this clearance is not controlled and kept substantiallyconstant, then grass clippings can dribble out from between grass basket140 and cutting reel 60 and be deposited in unsightly lumps on the mowedturf surface. For example, if cutting unit 28 can pitch or rock back andforth about the x axis while grass basket 140 does not, the gap betweenlower lip 186 of grass basket 140 and cutting reel 60 will obviouslygrow or shrink depending upon the direction of the rocking of cuttingunit 28. The clearance will vary and at times will be so large thatgrass clippings can easily escape down through this clearance.

The Applicants have solved this problem by taking advantage of the factthat the weight of grass basket 140, even when empty and also whenfilled with clippings, tends to rotate grass basket 140 down towardcutting unit 28 in the direction of the arrow K about the pivot axis x4.Grass basket 140 is allowed to swing down about the pivot axis x4 untilportions of grass basket 140, namely the lower triangular portions 188of the side walls of grass basket 140 adjacent to lip 186, abut againstthe front of the lower ends of pitch arms 54. This is shown in FIG. 28.When this occurs, the lower lip 186 of mouth 141 of grass basket 140will be maintained a very short distance, e.g. only an eighth of an inchor so, ahead of the nominal diameter of a new or unworn cutting reel 60.The nominal diameter of a new or unworn cutting reel is indicated as din FIG. 28.

Now, when cutting unit 28 pitches back and forth relative to the groundabout the pitch axis x, the clearance between lower lip 186 of mouth 141of grass basket 140 and the diameter d of cutting reel 60 will remainsubstantially constant. This is due to the fact that pitch arms 54, ormore precisely the pivot hubs 58 of pitch arms 54, are aligned with theaxis of rotation of cutting reel 60 so that the axis of rotation ofcutting reel 60 is the same as the pitch axis x. Thus, even thoughcutting unit 28 rocks relative to the pitch axis x, pitch arms 54 andthe front edge thereof have a constant unchanging relationship to thepitch axis x and thus to the axis of rotation of cutting reel 60. Byabutting a portion of grass basket 140 against the front edge of pitcharms 54, lower lip 186 of mouth 141 of grass basket 140 will stay at thesame relative clearance as is desirable even when cutting unit 28pitches back and forth about the pitch axis x.

The effect of this is to prevent the clearance between lower lip 186 ofmouth 141 of grass basket 140 and the outer diameter of cutting reel 60from varying. This clearance is kept substantially constant and can bekept very small to improve the flow of grass clippings from cutting reel60 into grass basket 140. There is little or no opportunity for grassclippings to fall through this gap or clearance. Thus, the after cutappearance of the mowed turf is improved since grass clippings will bemore effectively collected in grass basket 140 and will not fall outonto the turf. This is particularly important at the previously notedlow heights of cut prevailing on golf greens and given the extremedesire of golf course operators for a clean and uniform appearance ofthe mowed turf on a golf green.

In the event mower 2 did not have a counterbalance feature as describedin earlier herein, pivot axis x4 would be deleted. Grass basket 140would then pivot about pivot axis x5 to cause the abutting engagement ofportions 188 with pitch arms 54. Alternatively, if pivot axis x5 werenot available, some other horizontal pivot axis for grass basket 140would need to be provided on cutting unit carrier frame 52 or on someother portion of suspension 30. In addition, the controlled grass basketclearance feature could be deleted if desired in which case grass basket140 would be supported on cutting unit carrier frame 52 in a manner thatwould cause the spacing between the lip 141 and cutting reel 60 to varyas cutting unit 28 pitches about the pitch axis.

The Interleaved Sides of the Grass Basket and the Cutting Unit

Finally, referring to FIGS. 12, 21 and 23, side plates 96 of the frameof cutting unit 28 are no longer directly joined to the top wall of theframe of cutting unit 28 as in prior art mowers. Instead, top wall 190of cutting unit 28 is part of a U-shaped grass shield 192 in which topwall 190 extends between and is directly joined to a pair of verticallyextending side shields 194 at either end of top wall 190. These sideshields 194 extend downwardly to a level slightly below the top ofcutting reel 60. Side shields 194 are transversely spaced apart by adistance wider than cutting reel 60 so that the top of cutting reel 60can nest between side shields 194 of grass shield 192. Side plates 96are joined or fastened to grass shield 192 by a plurality of fasteningbolts that connect the rear of side plates 96 to the vertical sideshields 194 of grass shield 192 at locations generally rearwardly and/orabove cutting reel 60.

This allows a front slot 196 to be formed between side shields 194 andthe adjacent side plates 96 of cutting unit 28 with such a gap or slot196 being present on each side of cutting unit 28. Pitch arms 54 arelocated in this slot 196. When cutting unit 28 pitches back and forthabout the pitch axis x, pitch arms 54 are free to move back and forth inslot 196. As noted earlier, at some point during the lifting of cuttingunit 28 from its operative cutting position to its raised transportposition, the movement of pitch arms 54 within slot 196 will get stoppedout to lock up cutting unit 28 relative to the rest of suspension 30.But, at least during operation of cutting unit 28 in a normal mowingmode, pitch arms 54 can move rather freely within slots 196 as cuttingunit 28 pitches back and forth.

Now, it would be possible for the side wall portions 188 of grass basket140 to engage against the lower ends of pitch arms 54 even if slots 196between side shields 194 and side plates 96 were not present. This istrue because the sides of grass basket 140 need engage only against thelower ends of pitch arms 54. However, the Applicants have chosen to makeslot 196 open to the front and to use the separate U-shaped grass shield192 for a reason. Namely, the side wall portions 188 of grass basket 140can be made to telescopically fit into or to be interleaved into slots196. This interleaving is shown best in FIGS. 3, 22, and 27 where thetriangular lower side wall portions 188 of grass basket 140 fit betweenthe side shields 194 and side plates 96 on each side of cutting unit 28.

This interleaving engagement between side shields 194 of grass shield192 and the adjacent side plate 96 further improves the after cutappearance of the mowed turf since it presents a more tortuous path forthe escape of the grass clippings from inside grass shield 192 ofcutting unit 28. For grass clippings to escape to the side of cuttingunit 28 from inside grass shield 192, the clippings now have to travelaround the front edge of side shield 194, then pass rearwardly about theinterleaved side wall portion 188 of grass basket 140, then around therear edge of the interleaved side wall portion 188 of grass basket 140,and then forwardly back along the length of the interleaved side wallportion 188 of grass basket 140 before such clippings can pass outaround the front edge of side plate 96. Such a tortuous path makes ithighly unlikely the many grass clippings can escape through this path.Thus, fewer grass clippings can leak out through the sides of cuttingunit 28 but will be effectively collected in grass basket 140. This isan additional improvement that can be utilized to keep as neat and cleanan appearance for the mowed turf as is possible.

Use on Other Reel Mowers

The features described above can be used on reel mowers other than theone specifically shown in FIGS. 1 and 2. For example, the various grassbasket improvements would be useful on a walk reel mower, such as a walkgreensmower, having an upwardly and rearwardly extending handle assemblythat is gripped by an operator who walks behind the mower. Such a walkreel mower would typically have only a single cutting unit carried atthe front of the mower frame. Thus, the grass basket improvements couldbe used in conjunction with the greensmower shown in U.S. Pat. No.7,191,584 incorporated by reference herein, or on similar greensmowers.Similarly, the reel cutting unit of a walk greensmower can be easilyremovable from the suspension, and/or the motor can be easily removablefrom the frame of the reel cutting unit, both as also disclosed herein.

Moreover, the various features disclosed herein need not all be used atthe same time on a single mower. The mower designer can pick whichfeatures a particular mower should have on an almost ala carte basis.Thus, there are many possible permutations of features that woulddesirably be of interest.

Accordingly, the scope of this invention shall be limited only by theappended claims.

We claim:
 1. A reel mower for cutting grass, which comprises: (a) amower frame supported for rolling over the ground; (b) a power sourcecarried on the mower frame; (c) an operator's station carried on themower frame for supporting an operator thereon; (d) a plurality of reelcutting units carried on the mower frame; and (e) a suspension foroperatively connecting each reel cutting unit to the mower frame,wherein each suspension for each reel cutting unit includes a pair ofpivotal suspension arms extending substantially fore-and-aft relative tothe mower frame with the arms comprising an upper suspension arm and anunderlying lower suspension arm, wherein each suspension furtherincludes a steering head, wherein the steering head is operativelypivotally connected to one of the reel cutting units to allow the reelcutting unit to pitch relative to the steering head about asubstantially horizontal, laterally extending pitch axis and to rollrelative to the steering head about a substantially horizontal,longitudinally extending roll axis, wherein the upper and lowersuspension arms each have a bushing and ball joint pivotal connectionbetween a front end of each suspension arm and the steering head,wherein the bushing and ball joint pivotal connection of the uppersuspension arm is separate and distinct from the bushing and ball jointpivot connection of the lower suspension arm with the two separate anddistinct bushing and ball joint pivot connections comprising the onlypivot connections that act between the front ends of the suspension armsand the steering head, wherein the ball joints of the pivotalconnections of both suspension arms are vertically spaced from oneanother but sufficiently overlie one another when the reel cutting unitconnected to the steering head is in an operative mowing position todefine a substantially vertical yaw axis about which the steering headand the reel cutting unit connected to the steering head can yaw orsteer relative to the suspension arms during a mowing operation.
 2. Thereel mower as recited in claim 1, wherein each suspension arm isgenerally A-shaped when viewed from above in a top plan view having anapex and a pair of diverging sides or legs with the sides or legsterminating in distal ends that are spaced away from the apex in afore-and-aft direction, and wherein the front end of each suspension armcomprises the apex of the A-shape.
 3. The reel mower as recited in claim2, further including a pivotal connection between each distal end ofeach side or leg of each suspension arm and the mower frame.
 4. The reelmower as recited in claim 3, wherein the pivotal connection between eachdistal end of each side or leg of each suspension arm and the mowerframe comprises a bushing and ball joint pivotal connection.
 5. The reelmower as recited in claim 3, wherein the pivotal connection at eachdistal end of each side or leg of each suspension arm pivotally connectseach distal end of each side or leg of each suspension arm to the mowerframe for rotation of each suspension arm relative to the mower frameabout a substantially horizontal pivot axis such that pivoting of thesuspension arms about their respective pivot axes lifts and lowers thereel cutting unit out of and into engagement with the ground,respectively, between a lowered cutting position and a raised transportposition.
 6. The reel mower as recited in claim 5, wherein the reelcutting unit is lifted between the lowered cutting position and theraised transport position by rotation of the suspension arms through afirst angular range with the pivotal connections of the suspension armsremaining fixed to the mower frame during motion through the firstangular range.
 7. The reel mower as recited in claim 6, wherein the reelcutting unit is further lifted between the raised transport position anda tipped service position in which an underside of the reel cutting unitis tipped up to be substantially exposed to a person in front of thereel cutting unit by rotation of the suspension arms through a secondangular range beyond the first angular range, and wherein duringrotation of the suspension arms through the second angular range thepivotal connection of the upper suspension arm remains fixed to mowerframe while the pivotal connection of the lower suspension arm isreleased from the mower frame to allow the pivotal connection of thelower suspension arm to swing forwardly relative to the mower frame topermit the tipped service position to be reached.
 8. The reel mower ofclaim 1, wherein the vertical pivot axis is inclined or canted relativeto vertical at a negative angle that points rearwardly relative to thereel cutting unit and relative to vertical as one proceeds downwardlyalong the angle of inclination with such negative angle being presentwhen the reel cutting unit is in an operative, lowered cutting positionin engagement with the ground.
 9. The reel mower of claim 1, (e) whereineach suspension for each reel cutting unit includes a pair of pivotalsuspension arms comprising an upper suspension arm and an underlyinglower suspension arm, and wherein the upper and lower pivotal suspensionarms of each suspension are pivotally connected to the mower frame atone end thereof for rotation about upper and lower substantiallyhorizontal, transverse pivot axes to allow the pivotal suspension armsto lift and lower the reel cutting unit out of and into engagement withthe ground, respectively, between a lowered cutting position and araised transport position by a pivoting action of the suspension armsabout their respective transverse pivot axes, and wherein opposite endsof the upper and lower pivotal suspension arms are pivotally connectedto the reel cutting unit in a manner that permits the pivoting action ofthe suspension arms to cause the reel cutting unit to approach anddepart from the cutting position in an inclined, tail down orientationand to have a substantially more level orientation in the transportposition to increase the height of a rear portion of the reel cuttingunit above the ground from the height the rear portion of the reelcutting unit would have had if the reel cutting unit had not beenleveled out by the action of the suspension arms.
 10. A reel mower forcutting grass, which comprises: (a) a mower frame supported for rollingover the ground; (b) a power source carried on the mower frame; (c) anoperator's station carried on the mower frame for supporting an operatorthereon; (d) a plurality of reel cutting units carried on the mowerframe; (e) a suspension for operatively connecting each reel cuttingunit to the mower frame, wherein each suspension for each reel cuttingunit includes a pair of pivotal suspension arms comprising an uppersuspension arm and an underlying lower suspension arm; (f) a lift andlower actuator for each suspension that is separate and distinct fromthe upper and lower suspension arms of each suspension, wherein the liftand lower actuator for each suspension has an extendible and retractableactuator arm pivotally connected to one of the arms of each suspension;(g) wherein each suspension arm has a rear end that is pivotallyconnected by a pivotal connection to the mower frame for rotation ofeach suspension arm relative to the mower frame about a substantiallyhorizontal pivot axis such that pivoting of the suspension arms abouttheir respective pivot axes lifts and lowers the reel cutting unit outof and into engagement with the ground, respectively, between a loweredcutting position and a raised transport position, wherein the reelcutting unit is lifted between the lowered cutting position and theraised transport position by rotation of the suspension arms through afirst angular range with the pivotal connections of the suspension armsremaining fixed to the mower frame during motion through the firstangular range; and (h) wherein the pivotal connection at the rear end ofeach suspension arm is a two part pivotal connection comprising a firstpivot part on the suspension arm and a second pivot part on the mowerframe that provide pivoting motion therebetween, and wherein the reelcutting unit is further lifted between the raised transport position anda tipped service position in which an underside of the reel cutting unitis tipped up to be substantially exposed to a person in front of thereel cutting unit by rotation of the suspension arms through a secondangular range beyond the first angular range, and wherein duringrotation of the suspension arms through the second angular range the twopart pivotal connection of the upper suspension arm remains connectedthe mower frame while the two part pivotal connection of the lowersuspension arm is released as a unit from the mower frame withoutrequiring the first and second pivot parts of the pivotal connection tobe disassembled from one another to thereby allow the pivotal connectionof the lower suspension arm to swing forwardly in an assembled conditionrelative to the mower frame to permit the tipped service position to bereached.
 11. The reel mower of claim 10, wherein the two part pivotalconnection of the lower suspension arm is automatically released as aunit from the mower frame by operation of the lift and lower actuator ofthe suspension that connects the reel cutting unit to the mower frame.12. The reel mower of claim 10, wherein the two part pivotal connectionof the lower suspension arm is selectively releasable by the operatorthrough the activation of a control member by the operator.
 13. The reelmower of claim 12, wherein the control member is provided on a controlconsole at the operator's station.
 14. The reel mower of claim 10,wherein the two part pivotal connection of the lower suspension armcomprises a bushing that is pivotally journalled on a pivot formingmember.